<!DOCTYPE html>
<html>
    <head>
        <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
        <meta name="keywords" content="HTML, CSS, XML, XHTML, JavaScript">
        <meta name="description" content="Test on HTML and CSS">
        <meta name="author" content="Huoty">
        <meta http-equiv="refresh" content="30">
        <title>Web 设计</title>
        <link rel="shortcut icon" href="http://konghy.cn/favicon.ico" type="image/x-icon" />
    </head>
    <body>
JavaScript 数据类型学习！
    </body>
</html> 
<script type="text/javascript">
var bar;
console.log(bar);
console.log("hello");

function dir(obj){    
    var names="";       
    for(var name in obj){       
       names+=name+": "+obj[name]+", ";  
    }
    return names;
}

console.info(dir(console));
console.dir(console);
console.log(console);
console.table(console);

var v = null;
console.info(v);
console.info(v + 1);
console.info(v * 1);
console.info(v - 1);
console.info("hello" + null);

console.info(1/0);
console.info(Infinity);
console.info(-Infinity);
console.info(NaN);
console.info(Number);
console.info(Number.NaN);

console.info(NaN * 1);
console.info(NaN - 2);
//console.info(nan / 2);
console.info("NaN/10:", NaN/10);
console.info("NaN == NaN:", NaN == NaN);

console.info(typeof 1);
</script>
